Of Sno <sub> 2 </ Sub>, The In <sub> 2 </ Sub> The O <sub> 3 </ Sub> Nanostructures By Chemical Vapor Deposition Method And Their Field Emission, Photoluminescence, And Chemical Sensing Performance

Well aligned tin dioxide (SnO2) nanorod arrays and nanorods assembled flower-like microspheres have been directly grown on a single crystalline Si, conductive glass (FTO) and quartz glass substrate by low temperature CVD process. The Field emission (FE), photoluminescence (PL) and surface wettability of SnO2 nanorod arrays on Si substrate and gas sensing properties (toward to ethanol, acetone, ammonia and triethylamine) of SnO2 flower-like microspheres were investigated. Three-dimensional (3D) network structures and four-fold symmetry hierarchical nanostructures of indium oxide (In2O3) have been synthesized via in-situ growth process. Possible growth mechanisms were proposed to account for the growth of these In2O3 nanostructures. Gas sensing properties (toward to ethanol, acetone and triethylamine) of ln2O3 3D network structures have been investigated. These research results would provide a base for further research on synthesizes of SnO2 and ln2O3 nanostructures, the physical and chemical properties and their applications in photonic and electronic devices, gas sensor, photo detector. solar cell. Specific results are as follows.(1) Synthesis of SnO2 nanorod arrays and their FE, PL and surface wettability properties. Well aligned SnO2 nanorod arrays have been directly grown on a single crystalline Si, conductive glass and quartz glass substrate by the thermal evaporation of a mixture of stannous chloride dihydrate (SnCl2·2H2O) and anhydrous zinc chloride (ZnCl3) powders in air at 600℃, respectively. The controllable synthesis of SnO2 nanorod arrays with different size and growth direction was achieved by adjusting the heating temperature and the ratio of SnCl2·2H2O and ZnCl2 The growth mechanism of the nanorod arrays is briefly discussed. A comparative study of FE measurements between SnO2 nanorod arrays and polycrystalline films suggests that the microstructure of films is an important factor in determining the FE properties. Photoluminescence (PL) and surface wettability of the SnO2 nanorod arrays were measured at room temperature, and strong blue light emission with a peak at 424 nm was observed for the first time.SnO2 flower-like structures composed of nanorod have been synthesized via rapid thermal evaporation of the mixture of SnCl2·2H2O and ZnCl2 powders at low temperature of 600℃under air atmosphere. These nanostructures were characterized with scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). Moreover, the photodetector and sensor which based on flower-like nanostructure of SnO2 was fabricated by simple method, and the corresponding photo- and sensing properties towards ethanol. acetone, triethylamine and ammonia gas were investigated. This device exhibit high sensitivity for photodetector, and display good sensitivity, quite short response and recovery time for gas sensor.Three-dimensional (3D) network structures and four-fold symmetry hierarchical nanostructures of indium oxide (In2O3) have been in-situ growth on the surface of indium substrates by heating indium grains with As and ZnCl2 at 700℃under the flow of N2. The nanostructures have been controlled by adjusting location of As powder. The roles of As and ZnCl2 in the formation of In2O3 3D network structures have been investigated. The growth mechanism is briefly discussed. The gas sensing properties toward ethanol. acetone and triethylamine gas were investigated. The results shows that this nanostructures exhibit high sensitivity, quite short response and recovery time.